[omnibox chrome:omnibox] Add cursor position indicators.

When the query text input is not focused, an arrow is added below it to
indicate the cursor position. This is most useful when viewing imported
data or traversing response history.

Bug: 891303
Change-Id: Ib87a2d6d42211716181f1df073411530400eb3bd
Reviewed-on: https://chromium-review.googlesource.com/c/1394727
Commit-Queue: manuk hovanesian <manukh@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620719}
3 files changed